ip
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IPv4 Subnet Calculator

Enter an IP with a CIDR prefix or a subnet mask to see its network, broadcast, host range, and host count. You can also split the network into smaller subnets.

$ ipcalc
private IP (RFC 1918)10.167.203.128/25
network10.167.203.128/25
broadcast10.167.203.255
first host10.167.203.129
last host10.167.203.254
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.167.203.128/25
address00001010.10100111.11001011.10000000
subnet mask11111111.11111111.11111111.10000000
network00001010.10100111.11001011.10000000
broadcast00001010.10100111.11001011.11111111
green = network part, grey = host part
hex0x0aa7cb80
decimal178768768
reverse dns128.203.167.10.in-addr.arpa
ipv4-mapped::ffff:aa7:cb80

/25 split into /31 · 64 subnets

close ×
#networkhost rangebroadcast
110.167.203.128/3110.167.203.128 – 10.167.203.12910.167.203.129
210.167.203.130/3110.167.203.130 – 10.167.203.13110.167.203.131
310.167.203.132/3110.167.203.132 – 10.167.203.13310.167.203.133
410.167.203.134/3110.167.203.134 – 10.167.203.13510.167.203.135
510.167.203.136/3110.167.203.136 – 10.167.203.13710.167.203.137
610.167.203.138/3110.167.203.138 – 10.167.203.13910.167.203.139
710.167.203.140/3110.167.203.140 – 10.167.203.14110.167.203.141
810.167.203.142/3110.167.203.142 – 10.167.203.14310.167.203.143
910.167.203.144/3110.167.203.144 – 10.167.203.14510.167.203.145
1010.167.203.146/3110.167.203.146 – 10.167.203.14710.167.203.147
1110.167.203.148/3110.167.203.148 – 10.167.203.14910.167.203.149
1210.167.203.150/3110.167.203.150 – 10.167.203.15110.167.203.151
1310.167.203.152/3110.167.203.152 – 10.167.203.15310.167.203.153
1410.167.203.154/3110.167.203.154 – 10.167.203.15510.167.203.155
1510.167.203.156/3110.167.203.156 – 10.167.203.15710.167.203.157
1610.167.203.158/3110.167.203.158 – 10.167.203.15910.167.203.159
1710.167.203.160/3110.167.203.160 – 10.167.203.16110.167.203.161
1810.167.203.162/3110.167.203.162 – 10.167.203.16310.167.203.163
1910.167.203.164/3110.167.203.164 – 10.167.203.16510.167.203.165
2010.167.203.166/3110.167.203.166 – 10.167.203.16710.167.203.167
2110.167.203.168/3110.167.203.168 – 10.167.203.16910.167.203.169
2210.167.203.170/3110.167.203.170 – 10.167.203.17110.167.203.171
2310.167.203.172/3110.167.203.172 – 10.167.203.17310.167.203.173
2410.167.203.174/3110.167.203.174 – 10.167.203.17510.167.203.175
2510.167.203.176/3110.167.203.176 – 10.167.203.17710.167.203.177
2610.167.203.178/3110.167.203.178 – 10.167.203.17910.167.203.179
2710.167.203.180/3110.167.203.180 – 10.167.203.18110.167.203.181
2810.167.203.182/3110.167.203.182 – 10.167.203.18310.167.203.183
2910.167.203.184/3110.167.203.184 – 10.167.203.18510.167.203.185
3010.167.203.186/3110.167.203.186 – 10.167.203.18710.167.203.187
3110.167.203.188/3110.167.203.188 – 10.167.203.18910.167.203.189
3210.167.203.190/3110.167.203.190 – 10.167.203.19110.167.203.191
3310.167.203.192/3110.167.203.192 – 10.167.203.19310.167.203.193
3410.167.203.194/3110.167.203.194 – 10.167.203.19510.167.203.195
3510.167.203.196/3110.167.203.196 – 10.167.203.19710.167.203.197
3610.167.203.198/3110.167.203.198 – 10.167.203.19910.167.203.199
3710.167.203.200/3110.167.203.200 – 10.167.203.20110.167.203.201
3810.167.203.202/3110.167.203.202 – 10.167.203.20310.167.203.203
3910.167.203.204/3110.167.203.204 – 10.167.203.20510.167.203.205
4010.167.203.206/3110.167.203.206 – 10.167.203.20710.167.203.207
4110.167.203.208/3110.167.203.208 – 10.167.203.20910.167.203.209
4210.167.203.210/3110.167.203.210 – 10.167.203.21110.167.203.211
4310.167.203.212/3110.167.203.212 – 10.167.203.21310.167.203.213
4410.167.203.214/3110.167.203.214 – 10.167.203.21510.167.203.215
4510.167.203.216/3110.167.203.216 – 10.167.203.21710.167.203.217
4610.167.203.218/3110.167.203.218 – 10.167.203.21910.167.203.219
4710.167.203.220/3110.167.203.220 – 10.167.203.22110.167.203.221
4810.167.203.222/3110.167.203.222 – 10.167.203.22310.167.203.223
4910.167.203.224/3110.167.203.224 – 10.167.203.22510.167.203.225
5010.167.203.226/3110.167.203.226 – 10.167.203.22710.167.203.227
5110.167.203.228/3110.167.203.228 – 10.167.203.22910.167.203.229
5210.167.203.230/3110.167.203.230 – 10.167.203.23110.167.203.231
5310.167.203.232/3110.167.203.232 – 10.167.203.23310.167.203.233
5410.167.203.234/3110.167.203.234 – 10.167.203.23510.167.203.235
5510.167.203.236/3110.167.203.236 – 10.167.203.23710.167.203.237
5610.167.203.238/3110.167.203.238 – 10.167.203.23910.167.203.239
5710.167.203.240/3110.167.203.240 – 10.167.203.24110.167.203.241
5810.167.203.242/3110.167.203.242 – 10.167.203.24310.167.203.243
5910.167.203.244/3110.167.203.244 – 10.167.203.24510.167.203.245
6010.167.203.246/3110.167.203.246 – 10.167.203.24710.167.203.247
6110.167.203.248/3110.167.203.248 – 10.167.203.24910.167.203.249
6210.167.203.250/3110.167.203.250 – 10.167.203.25110.167.203.251
6310.167.203.252/3110.167.203.252 – 10.167.203.25310.167.203.253
6410.167.203.254/3110.167.203.254 – 10.167.203.25510.167.203.255
01 / table

IPv4 CIDR prefix table.

Click a prefix longer than your network to split it into subnets.

prefixsubnet maskaddresseshostsin your /25
/00.0.0.04,294,967,2964,294,967,294-
/1128.0.0.02,147,483,6482,147,483,646-
/2192.0.0.01,073,741,8241,073,741,822-
/3224.0.0.0536,870,912536,870,910-
/4240.0.0.0268,435,456268,435,454-
/5248.0.0.0134,217,728134,217,726-
/6252.0.0.067,108,86467,108,862-
/7254.0.0.033,554,43233,554,430-
/8255.0.0.016,777,21616,777,214-
/9255.128.0.08,388,6088,388,606-
/10255.192.0.04,194,3044,194,302-
/11255.224.0.02,097,1522,097,150-
/12255.240.0.01,048,5761,048,574-
/13255.248.0.0524,288524,286-
/14255.252.0.0262,144262,142-
/15255.254.0.0131,072131,070-
/16255.255.0.065,53665,534-
/17255.255.128.032,76832,766-
/18255.255.192.016,38416,382-
/19255.255.224.08,1928,190-
/20255.255.240.04,0964,094-
/21255.255.248.02,0482,046-
/22255.255.252.01,0241,022-
/23255.255.254.0512510-
/24255.255.255.0256254-
/25255.255.255.1281281261
/26255.255.255.19264622 split →
/27255.255.255.22432304 split →
/28255.255.255.24016148 split →
/29255.255.255.2488616 split →
/30255.255.255.2524232 split →
/31255.255.255.2542264 split →
/32255.255.255.25511128 split →
02 / faq

About this calculator.

How do I use this subnet calculator?

▼

Type an IP address followed by a prefix, like 192.168.1.10/24, or by a subnet mask, like 192.168.1.10 255.255.255.0. Without a prefix it uses /24. Click a row in the table to split the network into smaller subnets.

Why are usable hosts always 2 fewer?

▼

The first address in a subnet is the network address and the last is the broadcast address, so neither can go to a device. The exceptions are /31 (point-to-point links, RFC 3021) and /32 (a single address), which use every address.

Can I use it from a terminal?

▼

Yes. curl 'ipku.in/en/tools/ipv4-subnet-calculator?q=192.168.1.10/24' returns the result as plain text.

Learn how to work it out →